MBPC to caravan sizing

[cliffed]

Am I over thinking this, Pitch socket for caravan TT system 16 amp MCB, Rcd protection 30ma, supply 2.5 flex to DB in caravan also RCD protected.
What’s the requirements for the MBPC for the caravan,minimum requirement 6mm to the DB MET
With the supply cable 2.5mm flex this is not achievable, unless the earth electrode is situated at the caravan & not the pitch socket, or is it acceptable for connection at the DB

 

[loz2754]

Am I over thinking this, Pitch socket for caravan TT system 16 amp MCB, Rcd protection 30ma, supply 2.5 flex to DB in caravan also RCD protected.
What’s the requirements for the MBPC for the caravan,minimum requirement 6mm to the DB MET
With the supply cable 2.5mm flex this is not achievable, unless the earth electrode is situated at the caravan & not the pitch socket, or is it acceptable for connection at the DB

Obviously the pitch socket doesn't need main bonding.
Inside the caravan, regulation 721.411.3.1.2 applies -
"Structural metallic parts which are accessible from within the caravan shall be connected through main bonding conductors to the main earthing terminal within the caravan."
544.1.1 requires a minimum 6mm² main bonding conductor.

 

[cliffed]

Obviously the pitch socket doesn't need main bonding.
Inside the caravan, regulation 721.411.3.1.2 applies -
"Structural metallic parts which are accessible from within the caravan shall be connected through main bonding conductors to the main earthing terminal within the caravan."
544.1.1 requires a minimum 6mm² main bonding conductor.

Agree but the actual supply would only be a flex cable….
So if it’s a 100amp supply, 10mm MBPC required, It’s a TT system at the pitch socket, from that point would you take a MBPC to the caravan from there, to comply

 

[loz2754]

Agree but the actual supply would only be a flex cable….
So if it’s a 100amp supply, 10mm MBPC required, It’s a TT system at the pitch socket, from that point would you take a MBPC to the caravan from there, to comply

No.
The pitch socket has a separate earthing system, being TT.
The main bonding conductor needs to be not less than half the size of the earthing conductor of the TT system, subject to a minimum size of 6mm².

 

[UNG]

Am I over thinking this,

I think you are or a lot of portable appliances have a problem

 

[cliffed]

No.
The pitch socket has a separate earthing system, being TT.
The main bonding conductor needs to be not less than half the size of the earthing conductor of the TT system, subject to a minimum size of 6mm².

Agree

 

[cliffed]

I think you are or a lot of portable appliances have a problem

Agree senior moment…